Traction type hoist

ABSTRACT

A traction hoist of the type in which a rope is wound around a drum to provide a plurality of windings in side by side substantially parallel relationship. The shunting of the rope from one winding to the adjacent winding and the tensioning of the rope is accomplished by rollers so as to minimize power loss, provide automatic self-reeving action and to permit either end of the rope to be the tensioned end. Means is provided for indicating the presence of a damaged rope and for automatically shutting off the power in the event such damage is detected.

United States Patent [191 Arnold Aug. 26, 1975 TRACTION TYPE HOIST [75]Inventor: Carter H. Arnold, Palos Verdes Estates, Calif.

[73] Assignee: Western Gear Corporation,

Lynwood, Calif.

[22] Filed: Feb. 7, 1974 [21] Appl. No.-: 440,515

Related US. Application Data [62] Division of Ser. No. 207,374, Decv 13,1971, Pat. No.

[52] US. Cl 254/174; 226/45; 254/150 [51] Int. Cl. B66D 1/48 [58] Fieldof Search 254/150 R, 190 R, "174,

254/175, DIG. 11, 134.3 R; 242/47.0l, 47.12; 340/259, 260, 188; 73/144,143;

[56] References Cited UNITED STATES PATENTS 2,166,551 7/1939 Perry226/45 2,606,238 8/1952 lmshaug 340/259 2,873,117 2/1959 Crosfield226/45 2,917,279 12/1959 Arnold 254/150 R 2,922,623 l/l960 Simmons.....254/150 R 3,264,630 8/1966 Conklin 340/259 3,334,585 8/1967 Moran et a1.226/45 3,612,487 10/1971 Raney 254/174 3,722,773 3/1973 Geerardus et a1.226/43 3,749,327 7/1973 ROethke et a1. 242/47.12 3,785,176 l/l974l-lebbecker et a]. 242/47.01

Primary Examiner-Robert J. Spar Assistant Examiner-Kenneth Noland [57]ABSTRACT A traction hoist of the type in which a rope is wound around adrum to provide a plurality of windings in side by side substantiallyparallel relationship. The shunting of the rope from one winding to theadjacent winding and the tensioning of the rope is accomplished byrollers so as to minimize power loss, provide automatic self-reevingaction and to permit either end of the rope to be the tensioned end.Means is provided for indicating the presence of a damaged rope and forautomatically shutting off the power in the event such damage isdetected.

4 Claims, 3 Drawing Figures TRACTION TYPE I-IOIST This application is adivision of application Ser. No. 207,374 filed Dec. 13, 1971, now U.S.Pat. No. 3,791,626 issued Feb. 12, 1974.

This invention relates to an improved traction type hoist of the type inwhich a rope is wound around a drum to provide a plurality of windingsin side by side parallel relationship. The invention provides certainimproved features over the hoist disclosed in U.S. Pat. No. 3,707,275dated Dec. 26, 1972.

The main objects of the present invention are to provide an improvedtraction hoist of the subject type and also to provide a safety featurewhereby the power to the hoist is automatically shut off when the wirerope has an irregularity in its cross section deviating sufficientlyfrom normal to cause damage to the wire rope and to the hoist if thehoist were to continue to operate.

Other objects and advantages will be seen from the followingspecification and from the drawings:

FIG. 1 is a side elevation of the preferred form of the hoist with thefront plate removed to show the structure between the front and rearplates of the hoist.

FIG. 2 is a developed view of one side of the hoist showing the variousrollers in the position they take while the hoist of FIG. 1 is beingraised.

FIG. 3 is a view similar to FIG. 2 with the rollers omitted and showingthe rope in the arrangement it takes when the hoist is being lowered.

The general organization of the hoist housing, the power driven drum,and the arrangement of windings of the rope is generally similar to thatdisclosed in the above noted U.S. Pat. No. 3,707,275 and reference maybe made to said patent for details of construction not set forth herein.

The hoist housing is generally designated 101 and comprises a pair offront and rear side plates 102, 103 between which the drum 104 isrotatably supported and driven by the means indicated in said U.S. Pat.No. 3,707,275. The hoist herein described has a drum provided with sixgrooves but it will be understood that the number of grooves is notcritical. In the form shown in FIG. 1 one end 105 of the wire rope isshown extending upwardly from the drum 104 and, as best seen in FIG. 2,said end enters the groove in the drum which is adjacent the front sideplate 102. The rope is then wrapped around substantially the entireperiphery of thedrum until it is engaged by transfer roller 107 which,as best seen in FIG. 2, shunts the rope into the adjacent groove. Againthe rope is wrapped around substantially the entire circumference of thedrum until it engages transfer roller 108 which urges it into the thirdgroove. Once again the rope is wrapped around substantially the entirecircumference of the drum and is then shunted by a third transfer roller109 into the fourth groove.

The rope in the fourth groove engages the same for about only half thecircumference of the drum until it is shunted into the fifth groove bytransfer roller 112 at the lower side of the drum 104 as seen in FIG. 1.The rope in the fifth groove then extends around substantially theentire circumference of the drum until it is engaged by transfer roller111 which shunts it into the sixth groove in which the rope engages forsubstantially the entire circumference of the drum and then becomes thelower end 106 (FIG. 1).

It will be noted when the hoist of FIG. 1 is being raised with the drumrotating clockwise the portion of the rope connected with the tail end106 does not engage the remaining transfer roller which is disposedrelative to the points of tangency of ends 105,

106 in the same manner as the first mentioned transfer roller 107. Asnoted in the U.S. Pat. No. 3,707,275, one transfer roller is thusinoperative while the hoist is being driven in one direction and adifferent transfer roller becomes inoperative when the hoist is drivenin the reverse direction. In this case when the hoist is being raisedtransfer roller 110 is inoperative. However, as seen,in FIG. 3 when thedirection is reversed and the hoist is lowered then transfer roller 110operates to shift the rope from the groove adjacent rear side plate 103to the next groove. From FIG. 3 it will be seen that in such an eventthe rope is shunted into the first grooveby; transfer roller 108 andtransfer roller 107 then becomes inoperative.

By the present invention it will be seen that transfer rollers 107, 108and 109 are symmetrical, as a group, with transfer rollers 110, 111, and112 relative to the points of tangency of the ends 105, 106 of the wirerope. The close positioning of these two sets of upper and lowertransfer rollers insures that the first few windings adjacent each endof the rope engage the drum periphery to the optimum extent thusmaximizing the traction on the drum and at the same time permittingeither end of the rope to be the loaded end. This is extremely desirablein many instances and enhances the versatility of the hoist.

For the purpose of urging the rope against the periphery of the drum andthus increase the traction a plurality of tension rollers having theirperipheries yieldably urged against therope are provided between thetransfer rollers 109, 112 (FIG. 1). These tension rollers are designated1152-120. In addition, at the points of tangency of the ends 105, 106there is provided a tension roller 121 which, it will be noted from FIG.2 is provided with a plurality of grooves 122 in which the windings ofthe rope: are received. From FIG. 2 it will be apparent that tensionroller 121 is the only tension roller that engages'the'rope in all sixgrooves of the drum 104. It will be seen that in FIG. 2 the fourthgroove is empty for substantially half of its circumference while inFIG. 3 the third groove is empty for substantially half itscircumference. For this reason the tension rollers 115 to are notprovided with grooves at their central portions as is tension roller 121but said tension rollers 115-120 are recessed along their centralportions as indicated by dot-fdash lines on transfer roller 121 in FIG.2. This recessed portion is somewhat less in diameter than the bottomdiameter of the grooves 122 so that clearance is permitted for thewindings of the rope to move from the fourth groove to the third grooveand vice versa.

At this point it will be noted that reversibility of the As seen in FIG.2 the transfer roller 107 which shunts the rope from the first to thesecond groove is tilted relative to the drum axis so as to obtain asmooth transition of the rope from the first winding to the secondwinding. The actual degree of tilt varies with the diameter of the drumand with the diameter of the wire rope. For an 8 /2 inches diameter drumand 5/16 inch diameter wire rope the angle is preferably about 7V2. Toassist in this transition a reeving roller 125 is rotatably mounted on ashaft 126 secured to side plate 103. Said reeving roller 125 ispositioned closely adjacent transfer roller 107 and, since it wouldotherwise interfere with guide 128 of rope end it does not extend acrossthe entire width of the drum and is not supported on front plate 102.This reeving roller is provided with a curved surface 127 at its outerend which engages the end of the rope as the latter is reeved in thedirection shown in FIG. 2. By making the angle of tilt of roller 125about one half the angle of tilt of transfer roller 107 the desiredguiding of the rope is achieved. In this manner reeving roller 125directs the rope into the second groove where it is under the control,of the outer end of a similar reeving roller 130. Again, because of thepresence of the rope end 105, reeving roller 130 is cantilevered fromthe side plate 103 and is similarly formed at its outer end to assist inholding the rope in the second groove. It will be seen from FIG. 2 thatboth reeving rollers 125 and 130 are provided with additional groovessimilar to grooves 122 or tension roller 121 and which additionalgrooves are adapted to engage the remaining windings during reeving soas to prevent the rope end from taking its natural direction which wouldbe tangentially of the drum 104.

One of the features of the'instant hoist is that it may be reeved fromeither end. Thus if the rope is reeved from the opposite direction itwill be seen in FIG. 3 that cantilevered rollers 132, 133 operate in amanner similar to the above described cantilevered rollers 125, 130.

For the purpose of obtaining complete control over the wire as the sameis being reeved onto the drum 104 additional reeving rollers areprovided at spaced points around the periphery of the drum. These areindicated at 135-139 in FIG. 1.

The above described reeving rollers 121 and 135-139 are rotatablysupported on fixed axes and the same are not resiliently urged againstthe rope because their only function is to insure that the initialreeving step is carried out. For this reason when the hoist is inoperation these reeving rollers are not in engagement with the rope andthus are not called upon to resist a great amount of wear and thus maybe formed of fairly inexpensive plastic material.

It will be seen that the arrangement of shunt rollers, tension rollers,and'reeving rollers around the drum 104 as seen in FIG. 1 insurescomplete control over the v rope during the reeving process and insuresmaximum ther damage to the rope. This is particularly possible with thetransfer rollers because it is necessary that the same extend at theirperipheries well into the grooves of the drum in order to effect propershunting action. There is therefore a possibility that a transfer rollerwill pull through any portions of the wire that get between theperiphery of the roller and the bottom of the adjacent groove ratherthan staying on one side of the enlarged annular portion of the transferroller. In order to detect that portion of a damaged rope that may getbetween a transfer roller and the drum before it causes further damageand in order to prevent further operation of the hoist with damaged ropethe present invention includes a safety device which will now bedescribed.

The transfer rollers are supported on shafts which extend between theside walls of the hoist. By the present invention, the transfer rollersare yieldably urged radially inwardly of the drum in the same manner asthe tension rollers of FIG. 7 of US. Pat. No. 3,707,275. As best seen inFIG. 1 of the attached drawings, a light flexible cable 144 is fixed atone end to a bracket 145 and is reeved above the shaft of transferroller 109, then about a fair-lead 146, then about the shaft of transferroller 108, then around a fair-lead 147, then around the shaft oftransfer roller 107, and around a fair-lead 148 which guides the otherend of the cable upwardly through an apertured plate 149 fixedly securedto the housing. The cable 144 terminates in a socket 150 whichis springurged upwardly by spring 151. Similarly a second cable is provided witha socket 156 which is spring urged upwardly by a spring 157. This cable155 is guided by a fair-lead 154 to extend around the shafts of transferrollers 110, 111, 112 in a similar manner and around fair-leads 158,159. The stationary end of cable 155 is secured to a fixed bracket 161similar to bracket 145. In order to permit adjustment of the tension incables 144, 155, the fixed ends may be provided with externally threadedsockets 162 which are received through apertures in the flanges ofbrackets 145, 161, thereby permitting adjustment of the tension by meansof a nut 163 threadedly secured to socket 162. In this manner thetension in cables 144, 155 may be carefully adjustedso as to positionthe sockets 150, 156 closely adjacent an actuator arm 165 of a switch166 which may be in the circuit of the motor driving the hoist so as toopen said circuit upon engagement of the actuator 165 by either one ofthe sockets 150, 156. Alternatively the actuator 165 may also be aportion of the trigger mechanism of a rope gripping device such as thatdisclosed in U;S ."Pat. No. 3,669,223.

It will beapparent that if a'damaged wire or a strand thereof gets underany one of the six transfer rollers such transfer roller will be movedoutwardly by the wire rope against the yieldablemeans urging it inwardlythus relaxing the tension'in the associated cable 144 or cut orotherwise loses its uniform cross section there is a possibility incertain instances that the wire may get between the transfer rollers andthe drum causing furvice is actuated to stop the hoist motor or toactivate this manner positive actuation of the trigger or switch arm 165is insured even upon a slight radial outward movement of a transferroller.

Another feature of this safety device is that it operates in the desiredmanner regardless of the number of units with which it is employed. Inother words all of the elements whose movement is to be sensed canreadily be connected together so that movement of any one elementresults in the desired actuation. It will also be noted that nodifficult adjustment is necessary to properly position the sockets 150,156; it merely being necessary to turn the screw 163 until the socket150 or 156 is slightly spaced from the actuator 165.

The above described hoist thus includes positive means for controllingthe wire rope at closely spaced points around the entire length of therope that is in engagement with the drum. It will also be noted that therollers having special functions with respect to shunting the tensioningalso assist in the self-reeving operation. In this connection it will benoted that the transfer rollers in addition to being formed with theannular enlargement for shunting the wire rope are also provided withgrooves for engaging other windings of the rope so that at no point isthe rope permitted to deviate from the desired path of travel.

I claim:

1. In a hoist of the type that includes a drum, a rope reeved aroundsaid drum in a predetermined path of travel and an element having aportion thereof in engagement with said rope, when the latter is on saiddrum,

means for detecting a nonuniformity in the rope or a deviation of saidrope from said path to reduce the likelihood of damage comprising:

means for holding said element against said rope,

sensing means for sensing movement of said element away from said drumand means responsive to said sensing means for indicating said movementand for controlling the rotation of the drum.

2. Detecting means according to claim 1, wherein said sensing meansincludes an elongated flexible component in tension and having a portionof its length reeved around a portion of said element and connected atone end with said indicating means, whereby said movement of saidelement relaxes the tension in said component and actuates saidindicating means.

3. Detecting means according to claim 1 wherein said hoist includes aplurality of roller structures in engagement with said rope, eachconstituting a rope engaging element, and said flexible component isreeved about all of said plurality of roller structures.

4. Detecting means according to claim 1 wherein another rope engagingelement is provided, a fair lead interposed between said elements, saidflexible component being reeved about said fair lead and about saidelements whereby the movement of one element is multiplied in themovement of said flexible component.

1. In a hoist of the type that includes a drum, a rope reeved aroundsaid drum in a predetermined path of travel and an element having aportion thereof in engagement with said rope, when the latter is on saiddrum, means for detecting a nonuniformity in the rope or a deviation ofsaid rope from said path to reduce the likelihood of damage comprising:means for holding said element against said rope, sensing means forsensing movement of said element away from said drum and meansresponsive to said sensing means for indicating said movement and forcontrolling the rotation of the drum.
 2. Detecting means according toclaim 1, wherein said sensing means includes an elongated flexiblecomponent in tension and having a portion of its length reeved around aportion of said element and connected at one end with said indicatingmeans, whereby said movement of said element relaxes the tension in saidcomponent and actuates said indicating means.
 3. Detecting meansaccording to claim 1 wherein said hoist includes a plurality of rollerstructures in engagement with said rope, each constituting a ropeengaging element, and said flexible component is reeved about all ofsaid plurality of roller structures.
 4. Detecting means according toclaim 1 wherein another rope engaging element is provided, a fair leadinterposed between said elements, said flexible component being reevedabout said fair lead and about said elements whereby the movement of oneelement is multiplied in the movement of said flexible component.